Method of extracting rosin from



Reissued Nov. v 12, 1935' UNITED STATES warrior) or nxmc'rnro nosmmomruzsmous woen Leavitt N. Bent, Holly on. M, assignor m ner- Wilmington,

cules Powder Company,

corporation of Delaware No Drawing Original No. 1,sas,oz5, datedNovember 15, 1932, Serial No. 254,622, February Application for reissueSeptember 8,

1934, Serial No. 743,185

ISCIiI-lilil.

My invention relates toa method for extracting rosin from wood. I

As is well known,"a principal source of rosin is in stumps and down wood01' the long lea! pine 5 harvested i'rom cut over lands and subjected ina comminuted state to treatment tor the removal oi turpentine and pineoil and then to extractionwith gasoline, which acts to dissolve outrosin. 10 In accordance with prior practice the stumps and down wood arecomminuted to a suitable size and loaded into retorts or extractors inwhich the turpentine and part or the pine oil are removed by the use oflive steam. The Wood is then is subjected to extraction with a solvent,as a low boiling, petroleum hydrocarbon, which acts to dissolve out theremaining pine oil and the rosin.

"30 final steaming of the wood to effect separation of the solvent fromthe spent wood must be continually-rejected from the system. Heretoiore,petroleum-naphtha; or gasoline, has been considered the mostsatisfactory solvent, but such v is found to be open to a number oi!objections chief among which are that it is capable 01' extractlng inthe cold only about 75% of the resinous materialpresent in the wood, andthat when heated it constitutes a fire risk and re-;

4 quires a particulalr type of apparatus @101 its Now, in, accordancewith my invention, I

eflect the extraction 0! the resinous material 45 from wood by the useof a cold, water'miscible mixed with; acertain 'amountiori water, theconcentrationoi the solvent being'sudhthat it will dissolve out all wereresinous from the vwood andattheflsame time of; a cbncen' "tration suchthat wheng't irther diluted, y -moisture' in th 'e'wood, it may insubstantially its concentration bydistillation trom'a -simplestil1.

5;; Assolvents, the use or which I contemplate-in solvent, andmoreparticularly, 5 such a solvent the foregoing, example.

accordance with my invention, may be mentioned, for example, acetone,alcohol, methanol and the like, and the treatment of the wood with oneor another of the water miscible solvents in accordance with myinvention may be in accordance 5 with the usual practice at atmosphericor increased pressure and withthe use oi any ordinary .or desirable formof apparatus; The solvent when used will, as has been indicated, bemixed withwater to aconcentratlon enabling its recovery at substantiallyits original concentration by distillation from asimple stillanddepending upon. the particular solvent selected may be mixed withwater to a concentration of solvent within, for example, about the range65%-90%. More specifically, acetone may be desirably used at aconcentration of about 75%, alcohol at about Y80% and methanol at about80%.

As aspecific example of the carrying out of the'me'thod in accordancewith my invention wood chips, which normally contain about 15% 18% ofmoisture, are steamed in the usual manner for distillation ofl oi.turpentine, and

after steaming will contain about 20% of moisture. The wood chips aftersteaming are ex- 25 tracted with, 'for example, acetone mixed with waterto a concentration of about 75%. The acetone during the process ofextraction and solvent recovery will pick up suillcient moisture-fromthe wood chips to reduce its concentration from to about 70% and may becompletely re-. covered as acetone by rimning it through a simple stillin which the solvent will be separated from the rosin extracted.

As a further example of the carrying out of the 35 method in accordancewith my invention, pounds of pine wood, suitabLv chipped; is extractedwith say 232 pounds of asolution oi. acetone in water of a concentrationof say, for I example,'86% acetone. During the extraction heat may beapplied, through it will be understoodthat the application of. heat isnot necessary. The extraction may be carried out at atmosphericpressure. After a suitable period the acetone "solution, -.together withextracted 4 rosin, is drained from the wood and the woodmay be,re-extracted with say 235 pounds of 86% acetone solution, which inturn'isdrained Iromthe' wood and. ii desired, third, fourth and evenfirth my extractions may" be eflected. Extraction with) 86% acetonesolution, using say five extractions,

will be iound to remove from. 99% to 100% or the-aoetonesoluble'rosin,or about 23 pounds in the like,j than heretofore.

As an alternative method there may be added to the dilute acetonesolution of rosin sufiicient butane, pentane, or other water immisciblelow boiling petroleum hydrocarbon, which is not miscible with thesolvent, as'acetone, used for extracting the wood, and which ,has agreater sol-vent power on the rosin than has the solvent used forextraction of the wood in a closed vessel to prevent the volatilizing ofthe butane, to extract from this dilute acetone solution of rosin therosin content. Butaneand dilute acetonebeing substantially immiscible,two layers will be formed on settlement, the upper layer being a butanesolution of rosin, the lower being a dilute acetone solution containingdark colored resinous bodies. The lower layer is drawn oi! and distilledto rid it oi' the excess water picked up from the wood chips, and forthe recovery of dark colored r'osin and other extracted materials whichare soluble in acetone but not soluble in butane. The upper' duce anacetone of 74% concentration or approxi-.

mately of the same concentration as the original acetone and availablefor re-use in extraction.

As will be obvious the water miscible solvent, such as alcohol, acetone,etc., is not a good solvent for turpentine but is agood solvent for pineoil as well as for rosin. Consequently where a resinous wood containingturpentine and pine oil, 1. e., wood from which turpentine has not beenremoved, for example, by steaming, is extracted,

the turpentine will largely remain and will be separated from the woodby steaming, for example, in connection with recovery of. solvent fromthe wood, and may be readily refined by distillation. Pine oil containedby the wood will be largely dissolved out with the rosin and will .bereadily separated from the rosin and solvents by distillation. v

The method according to my. invention, and more especially the use of awater miscible solvent, will enable the extraction of substantially allthe resinous matter from wood chips and while the rosin recovered willbe found to-be darker than that obtained by prior methods, it maybereadily purified to a common or superior grade of rosin by distillation,by treatment with'selective solvents, by treatment with decolorizingearths or charcoal .or by other known methods. Further, due to the highpercentage extraction of rosin, the spent wood chips will be found moresuitable for use, for example, in'the manufacture of paper pulp, and

It will be understood that the figures given in theabove example mayvary considerably in practice for variousreasons, such as the moisturecontent of the wood chips treated, the quality of steam used, the of theextractor, etc., and it will within limits enabling recovery of thesolvent as described.

in; :wm .be understood am out the according to my inventiom-Icontemplate orother form of apparatus. v

. of asimple still for the recoveryof I vent. b the continuous evmq eron the rosin and which is immiscible and non-' reactive with the firstmentioned solvent, to the solution of rosin obtained, separating the lowboill0 .ing petroleum hydrocarbon anti dissolved rosin from the originalsolvent and distilling of! the low boiling hydrocarbon for the recoveryof rosin.

2. The method of extracting rosin from resinous wood, which includesextracting the wood with an alcohol solvent for the rosin, adding a lowboiling petroleum hydrocarbon, which has a selective sol-. vent power onthe rosin, to the solution of rosin obtained, separating the low boilingpetroleum hydrocarbon and dissolved rosin from the alcohol anddistilling oil the low boiling hydrocarbon for the recovery of rosin.

3. The method of extracting rosin from resinous wood, which includesextracting the wood with a monohydric alcohol a solvent for the rosin,adding a low boiling petroleum hydrocarbon, which has a selectivesolvent power on the rosin, to the solution of rosin obtained,separating the low boiling petroleum hydrocarbon and dissolved rosinfrom the monohydric alcohol and distilling oil? the low boilinghydrocarbon for the recovery of rosin.

4. The method of extracting rosin from resinous wood, which includesextracting the wood with methyl alcohol a solvent for the rosin, addinga low boiling petroleum hydrocarbon, which has a 35 selective solventpower on the rosin, to the solution of rosinobtained. separating the lowboiling petroleum hydrocarbon and dissolved rosin from the monohydricalcohol and distilling off the low boiling hydrocarbon for the recoveryof rosin. 4o

5. The method of extracting rosin from pine wood which includesextracting the wood with a water miscible organic aliphatic solventdiluted with water to a concentration within the range 15570-9070,extracting rosin from the solution ob- 45 tained with a low boilingpetroleum hydrocarbon which is immiscible and non-reactive with thesolvent, separating the low boiling petroleum hydrocarbon and extractedrosin from the original solvent and distilling oil the low boilinghydro- 5 carbon for the recovery of rosin. v

. 6. The method of extracting rosin from pine wood which includesextracting the wood with a water miscible organic aliphatic solventdiluted with water to a concentration within the range 66 %-90%.extracting rosin from the solution'ob Y tained with a lbw boilingpetroleumhydrocarbon which is immiscible and non-reactive with thesolvent, separating the low boiling petroleumhydrocarbon and extractedrosin from the original 00 solvent, distilling oil the low boilinghydrocarbon for the recovery of rosin and distilling the originalsolvent. Y v

"l. The method of extracting rosin from pine wood which includesextracting the wood with 66 an alcohol diluted with water, extractingrosin from the solution obtained with a low boiling petroleumhydrocarbon which is immiscible with, the diluted alcohol, separatingthe low boilingi petroleum hydrocarbon and extracted rosin from 70 theoriginal solvent and distilling on the low boiling hydrocarbon for therecovery of rosin.

8. The method of extracting rosin from-pine wood which includesextracting the wood with Amethyl alcohol diluted with water, .entrsat1nrosin from the solution obtained with a low boiling petroleumhydrocarbon which is immiscible with the diluted methyl alcohol,separating the low boiling petroleum hydrocarbon and extracted rosinfrom the original solvent and distilling oil the low-boiling hydrocarbonfor the'recovery' oi the rosin. x

9. The method of extracting rosin from pine wood which includesextracting the wood with an alcohol diluted with water to aconcentration of about 80% extracting rosin from the solution obtainedwith a low boiling petroleum hydrocarbon which is immiscible with thediluted alcohol separating the low boiling .petroleum hydrocarbon andextracted rosin from the original solvent and distilling oil the lowboiling hydrocarbon ion the recovery or rosin.

10. The method of extracting rosin from pine wood which includesextracting the wood with an organic solvent for the rosin which ismiscible with water, adding a low boiling petroleum hydrocarbon, whichhas greater solvent power on the rosin and which is immiscible with thesolvent used, to the solution of rosin obtained, separating the lowboiling petroleum hydrocarbon and dissolved rosin from the originalsolvent and distilling on the low boiling hydrocarbon for the recoveryof rosin.

11. The method 01' extracting rosin from pine wood which includesextracting the wood with a water miscible organic aliphatic solvent forthe rosin diluted with water, extracting rosin from the solutionobtained with a low boiling petroleum hydrocarbon which is immiscibleand non-reactive with the solvent used and separating the low boilingpetroleum hydrocarbon and extracted rosini'rom the original solvent anddistilling of! the low boiling hydrocarbonior the recovery oi.

12. The method of extracting rosin from pine wood which includesextracting the wood with acetone diluted with water, extracting rosinfrom distilling oil the low boiling hydrocarbon for the 5 recovery 01'rosin.

13. The method of extracting rodn from pine wood which includesextracting the wood with acetone diluted with water, extracting rosinfrom the solution obtained with butane, separating the butane andextracted rosin from the acetone and I distilling oi! the butane iortherecovery of the rosin.

14. The method of extracting rosin from resinous wood, whichvincludesextracting the wood 16 with an organic aliphatic solvent for the rosinwhich is miscible with water, adding a low boiling petroleumhydrocarbon, which has selective solvent power on the rosin and which isimmiscible and non-reactive with the first-mentioned sol- 20 vent, tothe solution of rosin obtained, separating the low boiling petroleumhydrocarbon and dissolved rosin irom the original solvent, distillingofl the low boiling hydrocarbon for the recovery 0! rosin and heatingthe wood to a temperature such as to remove organic water-misciblesolvent therefrom.

15. The method of extracting resin from resinous wood, which includesextracting the wood with an organic aliphatic solvent for the rosinwhich is miscible with water, adding a low boiling petroleumhydrocarbon, which has selective solvent power on the rosin and which isimmiscible and non-reactive with the first mentioned solvent, to thesolution of rosin obtained, separating the low boiling petroleumhydrocarbon and dissolved rosin from the original solvent, distillingoi! the low boiling hydrocarbon for the recovery of rosin and steamingthe wood for theremoval 0! organic water-miscible'solvent therefrom. 0

mavrrr n.

